Use of heat from the fireplace using a recovery unit

Quite a few of you are asking, or wants to solve the problem of how best to dissipate excess heat from the fireplace in a family home. The fireplace is usually located in the living room, where there is a risk of overheating, especially in passive houses. For distribution, there is no need to buy noisy fans and uncleanable pipes that some suppliers recommend. A recuperation unit can also be used for this purpose.

Basic conditions for a successful installation:

- space for SPIRO pipes with a larger diameter (125, 160, 200mm) + ensuring non-flammability of the surroundings
- the distance between the unit and the fireplace is not too large
- the ventilation recuperation unit supports zone regulation or indoor air circulation, but it is also possible to control the servo drive by other controls
- space for a mixing valve and a possible service opening for cleaning

Recommended solution A – conventional passive ventilation recovery unit:

A mixing valve (e.g. MSKM MIX ) with a servo drive is installed on the discharge branch (from the house to the unit) behind the silencer. The main route leads to the bathrooms, WC, kitchen, dressing rooms, etc. The second route leads to the fireplace. We will keep it closed most of the time and open it only when necessary - to use the fireplace.

On the unit, in weekly mode or manually, we set the start of extraction from the fireplace (zone activation). Such regulation is offered, for example, by Atrea Duplex units with RD5 regulation (new aM). It is therefore a solution where the heated air is blown into the recuperator and it largely transfers the heat to the supply fresh air, which is distributed throughout the house. Since the recuperator does not return 100% of the heat, part of the heat is blown away from the house. Despite the cost of this heat loss, it is sometimes the only possible way to distribute the excess heat from the fireplace, without major interventions in the ceilings, etc.


The examples of our projects below show a possible solution to the situation.


Example solution #1:




Example solution #2:


Example solution 1:


Recommended solution B – ventilation recovery unit with circulation:

This is a more efficient solution. The warm air from the fireplace is led up to the unit, which has multiple nozzles. The unit has the option to choose whether the air circulates around the house and efficiently distributes heat or whether it is in normal recovery mode. These units can often be retrofitted with a heat pump for cooling and reheating.

This is made possible, for example, by recuperation units of the DUPLEX RA5 type with five ports. Circulation is enabled, for example, by the Jablotron Futura .



Recommended solution C - circulation for DUPLEX EC5/ECV5 units

In this case, the possibility of circulation in DUPLEX EC5 / ECV5 units is described using a mixing valve (e.g. TKR LM24 ) fitted with a servo drive for fresh air intake from the exterior. A side route from the mixing flap leads to the fireplace (ideally in galvanized SPIRO piping ) and is terminated with a heat-resistant end element (e.g. GAC 300x100 grid ).


The mixing valve is controlled by an external switch. When the switch is closed, the exhaust from the interior and the exhaust to the exterior are closed. The unit therefore does not ventilate but circulates and distributes excess heat from the fireplace throughout the house.


The possibility of using a heat exchanger




What to watch out for:

- at high temperatures - air cannot be sucked in from the fireplace insert - temperature too high. It is necessary to pay attention to the temperature resistance of all elements of the system, including the unit. We recommend really mixing not switching branches ON/OFF. The temperature at the ceiling above a conventional fireplace often reaches significantly above 100°C.

- always bring your own combustion air outside the recovery system to the fireplace. Usually galvanized square pipe. This too can be regulated, for example, by a valve with a servo drive.

- when most of the air volume is removed from the living room, a greater negative pressure is created, which may not be equalized as easily as during normal operation. We recommend keeping open doors to other overpressured rooms/corridors so that the negative pressure is reduced and that no fumes escape into the living room when putting it on fire. Alternatively, the function (A zone and or B circulation) can be deactivated for a while to place it in the fireplace.

- cleaning of the system - the suction grill near the fireplace and the pipe distribution must be cleaned

- don't forget the cabling between the unit and the servo drive. Select the servo drive according to the control type (unit, etc.)


What can be added for more comfort when using the fireplace:

- overpressure button – the unit supplies more air than it removes. It manifests itself in a better draft of the chimney during ignition. Can be set with a time delay similar to boost.

- filter box with higher heat resistance, which saves you money when replacing filters in the unit

- depending on the type of unit, room temperature sensor switching can be solved


Components used in the examples shown:

GAC wall grid


SONO pipes - SPIRO can also be used for better cleanability


MSKM MIX mixing valve


Lufberg servo drive 0-24 V



Published on: 5/18/2020

Authors of the article: Ing. Pavla Skalická, Ing. Tomáš Trávníček - Luftuj sro




Video of the Luftuj - Aquatherm Prague 2024 booth

Which servo drive to choose for electronically controlled flaps in the recuperat

We are rooting for Kristýna Otcovská at the European Championships in biathlon i

Fly to Aquatherm 2024, Prague

New presentation video of the company Luftuj sro

Christmas holidays - all-race vacation

We lectured at the 2023 Ventilation and Air Conditioning Conference

Visit us in September at the ForArch trade fair in Prague

Atrea comes with a new generation of Duplex Pro and Pro-V units

HOLIDAY 5.-7.7.2023

We trained...

VACATION 5-9/6/2023

Fly for the first time at ISH in FRANKFURT n/M

DUPLEX units switch to a new generation of regulation

An example of self-help installation of recuperation pipelines in a residential

We lectured at the STP seminar - How to prepare the recuperation system for serv

Thank you for visiting our stand at For Arch 2022

Fight at FOR ARCH 2022

5% discount for the whole of June

Aquatherm Prague 2022 news

We start tomorrow - Aquatherm 2022 is just starting

Luftuj at Aquatherm in Prague 19-22 April 2022

EPE x ADURO part 1

EPE x ADURO part 2

The website for Slovakia is being prepared


Pipeline recuperation in bungalows

The end of the year marks the completion of construction, service and projection

Recovery and direct extraction from the toilet bowl

New photo studio and print farm


Tool for cutting flexible pipe

New articles in the advisory

Intake and exhaust recovery

Use of heat from the fireplace using a recovery unit


Shields for hospitals - production started

Filters and recovery during the COVID-19 pandemic

Filter fabrics F7 and filter bags - SALE STOPPED


Implementation of ventilation with recuperation in SVATOŇOVICE Kindergarten and

We are starting the sale of Globovac Play central vacuum cleaners


Filters for recovery


Implementation process

Cleaning the air conditioning system of a family house

Comparison of local recovery units

Recuperator and recuperation efficiency

Preheating for recovery

Central vacuum cleaner - why?

Installation of a central vacuum cleaner

Central vacuum system piping installation

Self-help recovery II

Self-help recovery I

Recovery vs. air conditioning

Recovery vs. hood

How the recuperator and the recuperation unit are made

We are testing

Recovery service

Self-help recovery

What is recovery

What pipes for the recovery system?

Best seller

Nastavení Cookies

Naše webové stránky používají soubory cookies, které nám pomáhají s jejich vylepšováním. Abychom cookies mohli používat, musíte nám to povolit. Kliknutím na tlačítko "OK, souhlasím" udělujete tento souhlas.

Nastavení OK, souhlasím
Nastavení souborů cookies

Cookies jsou malé soubory, které webové stránky (i ty naše) ukládají ve Vašem webovém prohlížeči. Obsahy těchto souborů jsou vyměňovány mezi Vaším prohlížečem a našimi servery, případně se servery našich partnerů. Některé cookies potřebujeme, abychom webová stránka mohla správně fungovat, některé potřebujeme k marketingové a statistické analytice. Zde si můžete nastavit, které cookies budeme moci používat.

Nezbytné cookies
Nezbytné cookies
Jedná se o technické soubory, které jsou nezbytné ke správnému chování našich webových stránek a všech jejich funkcí. Používají se mimo jiné k ukládání produktů v nákupním košíku, zobrazování produktů na přání, ovládání filtrů, osobního nastavení a také nastavení souhlasu s uživáním cookies. Pro tyto cookies není zapotřebí Váš souhlas a není možné jej ani odebrat.
Ovlivňuje funkce:
  • Konfigurační cookies
Analytické cookies
Vypnuto Zapnuto
Analytické cookies
Analytické cookies nám umožňují měření výkonu našeho webu a našich reklamních kampaní. Jejich pomocí určujeme počet návštěv a zdroje návštěv našich internetových stránek. Data získaná pomocí těchto cookies zpracováváme souhrnně, bez použití identifikátorů, které ukazují na konkrétní uživatelé našeho webu. Pokud vypnete používání analytických cookies ve vztahu k Vaší návštěvě, ztrácíme možnost analýzy výkonu a optimalizace našich opatření.
Ovlivňuje funkce:
  • Google Analytics - analytická návštěvnost
Personalizované cookies
Vypnuto Zapnuto
Personalizované cookies
Používáme rovněž soubory cookie a další technologie, abychom přizpůsobili náš obchod potřebám a zájmům našich zákazníků a připravili tak pro Vás výjimečné nákupní zkušenosti. Díky použití personalizovaných souborů cookie se můžeme vyvarovat vysvětlování nežádoucích informací, jako jsou neodpovídající doporučení výrobků nebo neužitečné mimořádné nabídky. Navíc nám používání personalizovaných souborů cookie umožňuje nabízet Vám dodatečné funkce, jako například doporučení výrobků přizpůsobených Vašim potřebám. 
Marketingové cookies
Vypnuto Zapnuto
Marketingové cookies
Marketingové (reklamní) cookies používáme my nebo naši partneři, abychom Vám mohli zobrazit vhodné obsahy nebo reklamy jak na našich stránkách, tak na stránkách třetích subjektů. Díky tomu můžeme vytvářet profily založené na Vašich zájmech, tak zvané pseudonymizované profily. Na základě těchto informací není zpravidla možná bezprostřední identifikace Vaší osoby, protože jsou používány pouze pseudonymizované údaje. Pokud nevyjádříte souhlas, nebudete příjemcem obsahů a reklam přizpůsobených Vašim zájmům.
Ovlivňuje funkce:
  • Google Ads